Tie rod construction



O mile-11., 1935- J. H.STEENsoN 2,004,398

TIE ROD CONSTRUCTION Filed July 23, 1932 2 Sheets-sheet l IN V EN TOR.:L4/W55 /z/ FEA/50N A TTORNEY June 11, v1935. J. H. sTEENsoN TIE RODCONSTRUCTION Fiied July 25, 1932 2 Sheets-Sheet 2 Il, l I' 'im IMQ@INVENTOR.

Patented .lune 11, 192.5y i l 2,004,398

,UNl'rl-:D 'STATES PATENT OFFICE James n. Swenson, Plainfield, N. J.,assigner to Breeze Corporations, Inc., Newark, N. J.

Application July 2s, 19`3z, serial No. 624,321 s claims. V(el. 281-62)This invention relates to tie rod construction which the rod does nothave to be rotated' to and the object is broadly to provide aconstrucinstall or service the same.

tion which is eii'ective under conditions of ex- In some of the arts tierods and their connectreme vibration and varying stresses by reasontions are made up in large stocks, of varying 5 of tension and/orcompression; materials and dimensions, and it is necessary to 5 Wheretie rods are not of uniform cross section distinguish betWen them.Therefore, One Object fatigue and other stresses are localized at pointsof the invention is to provide'a means for receivwhere the areas incross section are reduced and ing indicia Clearly applied to the red and00mresultant breakage occurs. Therefore, one of bined with a lockingmeans which may be easily l0 the objects of the invention is to providea conapplied and removedstruction which eliminates this localization ofA further Object 0f the lrVenlilOn iS t0 DI'OVide fatigue and otherstresses, and at the same time a tie red in Which n0 tenSiOn iS appliedt0 any permits the vibration actually set up in .the use threaded part0n the red and t0 have the red of a tie' rod. of uniform cross sectionfrom end to end.

In the use of tie rods the stresses are frequently Another object 0f theinventlen iS t0 prOVide a 15 varied so that the tension 10nd on the rodis tie rod with spherieally formed ends which may changed to acompression load. This frequently be Seated in correspondinglySpherically formed results in distortion o! the tie rod. Therefore,Seat-f 0f an adlustably eonnecting need S0 as t0 one object oi' theinvention is to provide a conelmlnete the Possibility 0f lnpOSlngeccentric 2o struction which will eliminate this condition and loads onthe spherically formed ends oi the rod to provide a construction whichwiii pei-miil a which loads may be caused by vibration or dechange oftension loads on the tie rod and to preflecnon 0f Varying amplitudenvent imposition oi compression loads. and at the *A further Object 0fthe invention is t0 Drosame time which will void distortion -of the rodvide a construction for adjustment between the by reason of compressionscrew threaded connecting members of the tie rod In tie rods constructedwith soi-ew threaded of such design and proportion as to eliminate theends, made up in stock sizes, in order to modify possibility of theexchanging of the tension for a the llength of the rod the ystructuremusi; be compression load, and at the same time embody a modined; Forinstanoe, where there is the usual shear value of the screw threadsunder strain 3o square tie rod with screw threaded areas at its Whichgreatly exceeds that Provided in designs 30 ends the screw threaded endswould have to be 110W in general' Secui; on and the ends refomied andsorew- A further object of the invention is to provtin-@mimi This hesproved' unsatisfactory and vide a construction which may be installed,inhas resulted in the accumulation of large stocks sPected adlusted andreplaced, by Single 'mmf' as of unsuitable tie rods which ultimatelyhave to dual 0r Workman' particule 1n airplane Pm' as be scrappedresulting in large losses en tice. Under ordinary practlceairplanetierods iore, one object oi'v this invention is to provide are made angularm cross section and have screw a construction m which the length may be.modi threaded ends. These screw threaded ends enmnm gage in interiorlyscrew threaded sleeves of a 4o 3?: rzidthout ying the body structure ofclevis at each end. The screw threaded ends are 40 respectively providedwith right and left screw A further b5t 0f the invention s t0 Prmdethreads, and installation of such latter tie rods a visible indicationwhich wm eectlvely show requires two men to hold the rod in position tobe that the required minimum engagement of the installed and to tightenthe ends to provide the rOd t0 its e0nheetin8 eleviS has been effected,S0 necessary tension, and when the load is changed 8S t0 eliminate anydnnel' that Sumeienli en' from a tension to a compression load the rodis sagement has not been made in assembling and necessarily distorted.Therefore, one oi' the observiclng the parte. jects of the invention isto avoid this undesirable A further object oi the invention is toprovide condition.

. 5o a construction where a threaded adjusting mem- In the drawingsforming part of this applicaoo ber has its material at the root of itsthread tion I have illustrated the application of the inundercompression instead of under tension. vention to airplane construction,but it will be A further object of the invention is to provideunderstood that the object of the invention is to a construction inwhich the lock nut does not provide a construction applicable to anycondioo impose any load directly on the tierod and in tion where aconnecting member is subjected to 55 tension or by variation tocompression, and where the loads are of varying values.

The invention consists of the construction, combination and arrangementof parts, as herein illustrated, described and claimed.

In the accompanying drawings, forming part hereof, is illustrated a formof embodiment of the invention, as applied to airplane construction, inwhich drawings similar reference characters designate correspondingparts, and in which:

Figure l is a perspective, partly broken away, showing the applicationof the invention to an airplane wing;

Figure 2 is a perspective showing the parts o one end of a tie rod andits connections, separated;

' Figure 3 is a longitudinal section through the connecting parts andshowing one .end of a tie rod in elevation, the parts being shown intheir relative assembled position;

Figure 4 is a perspective view showing the parts separated andillustrating the removable means for locking the parts together withoutthe use of a lock-nut, and providing a means for carrying indicia inconnection with the lockingmeans;

Figure 5 is a longitudinal section of the parts illustrated in Figure 4,but in assembled arrangement;

Figure 6 is a perspective showing the parts separated and illustrating amodied means for indicating a required minimum engagement of the screwthreaded parts; and,

Figure 7 is a longitudinal section Vthrough the parts illustrated inFigure 6 assembled in their relative working condition.

Referring to the drawings, A designates vthe longitudinal frame membersof an airplane wing Which are connected by transverse ribs B. Carried byand connecting the ribs B are spars C between whichare disposedcompression bars D. Secured to the spars C at intervals are fittings Eadapted to receive the ends of the compression bars D. Secured to eachfreev end of each of the fittings E is a clevis F removably secured inposition by means of a pin G. The clevis F is provided with an internalscrew threaded sleeve H in each instance and the wing is covered by afabric covering I. Ordinarily to indicate the depth of the tiev rod inthe sleeve H an opening J is provided in the Wall of the sleeve H topermit the insertion of a wire or other small instrument so as trindicate when a required minimum engagement between the`parts has beenobtained.

In ordinary construction' the tie rod itself is usually an angular'metal body having its ends round in cross section and provided 4with.screw threads.

All of the foregoing construction designated by letters is old and wellknown in the art and is described merely to show the application of theinvention.

Referring tothe drawings and to illustrate one form of my invention, 8designates a tie rod, preferably round in cross section and uniform incross section throughout its entire length so that any stress appliedthereto will not be localized in any portion of less cross section thanits adjacent body. As disclosed, the object of Athis is to increase thefactor of safety against breakage under stress.

On each end the rod 8 is provided with an integral head 9 formed byupsetting the metal of the body of the rod 8 and the inner face of thehead 9 is formed with a face" I il spherical in contour and graduallymerging into the body of the rod 8 so as not to Ileave any abrupt edgein cross section, thus again eliminating localization of stress andincreasing the factor of safety from breakage, and eliminating thepossibility of imposing an eccentric load on the heads due to vibrationsor deflections when used in connection with a corresponding sphericalbearing hereinafter described.

At the time of manufacture 'of the rod 8 there are disposed thereon twosleeves II, one for each end of the rod. The sleeve I.I is provided withexternal screw threads I2 adapted to engage the internal screw threaded'sleeve H of the clevis F. The screw threads I2 perform the additionalfunction of receiving the lock nut I3, the threads of the sleeve H andthe threads I2 of the sleeve II and the threads of the lock nut I3, allbeing uniform effects a material reduction in the cost of production.

For a portion of its length the sleeve II is provided with ilattened orangular surfaces I4. 'I'hese surfaces are designed to be engaged by asuitable turning tool or instrument, such as a wrench and to perform theadditional function that when thesleeve I I has been'screwed into thesleeve H to a point where the inner ends of the flattened surfaces I lregister with the outer end of the sleeve H, the workman hasautomatically indicated to him that the required or suicient minimumengagement of the threads of the parts has been attained so that theassembly of the parts is made fool proof, and the factor of safetyrequisite is obtained. It is known in the art .to have the opening J inthe sleeve H and to use an instrument as a probe to ascertain whetherthe rod 8 has` been brought into sutlicient engagement, but the attenedsurfaces I4 give this indication automatically.

The outer ends of the sleeves II are each provided with a recess orsocket I5, coincident in size and radius with the inner faces I0 of themembers 9, so that the loads of the stresses imposed on the rod 8 areequally distributed to the end of the sleeve II, and avoids imposing ofeccentric loads due to varying vibrations or deections.

The inner ends of the sleeves II are each provided with a bore I6 andthe outer ends are pro'- vided with a continuing bore I1 o f lessdiameter. The rod 8 is disposed through these bores and, as is wellknown in use, its vibrations increase from the focal point in the centerof the head I0 to a point midway its ends. 'I'he bore I8 is made largerto permit this vibration and the bore I1 is made smaller so as to checkexcessive vibration immediately adjacent .the ends.

In the construction `shown in Figures 4 and 5 the lock nut I3 iseliminated and for it is substituted a sleeve of substantially softmetal I8 adapted to be' slid over the sleeve Il after-it has' beensecured in the desired minimum engagement with the sleeve H.v

The outer end of the sleeve I8 may be upset to form ears 2l to engagebetween the walls of lthe slot of the clevis F to retain the sleeve I8in servable for the purpose of inspection so that indicia I8a for thatpurpose may be imposed on the sleeve I8, so that the sleeve I8 performsa triune function, to wit, effects a locking of the parts together,indicates a required minimum engagement Iof the parts and affords amedium for indicia.

In the form of construction in Figures 6 and 7 the sleeve II has itsscrew threads I2 of a length required to effect a minimum engagement inorder to provide the proper factor of safety so that when it is engagedin the sleeve H to a point where the shoulder formed by its reducedscrew threaded end 22 is even with or inside of the end of the sleeve Hit automatically indicates the proper adjustment of the parts. Further,by having the reduced -screw threaded end 22 a reduction of weight iseffected in the part and a smaller .and lighter lock nut I3 may be used,which is desirable in all parts of airplane construction where thefactor of safety is notlowered.

The operation of the parts and the physics in-A volved will be apparentfrom the foregoing disclosure, and the objects attained'obvious to thoseskilled in the art to which the invention appertains.

In using the invention the rod or Wire 8 is produced..with a uniformcross-section throughout. The rod 8 is introduced through the sleeves II and in the instance of the construction shown in Figures 4 and 5,through the sleeves I8. 'I'hisin itself produces a complete article ofmanufacture.

To install the device the sleeve II is introduced into the sleeve Htothe point where the end of the flattened portion I4 registers with theAend of the sleeve H, and the lock nut I3 is tightened to secure theparts.

In the form shown in Figures 4 and 5 the lock nut I3 is dispensed withand the sleeve I8 per- 'forms the function of the nut, the ears 2|holding same against rotation. In all of the forms the surfaces I4 orthe reduced portion 22 (Figures 6 and 7) indicate the required minimumengagement of the parts.

For inspection it is necessary to remove only a limited area of thefabric I and a single workman may make the installation or adjust thetension on the rod 8.

It is apparent that when the load on the rod 8 is reversed from tensionto compression that the rod will slide through the sleeve II and willnot be distorted.

It will also be apparent that the rod 8 being of comparatively smallcross -section has no screw threads but is held by its spherical headco-acting with the spherical seat in a` sleeve having a large screwthreaded area, thus insuring an excess of shear resistance,-andincreasing the factor of safety, and reducing production costs.

It will also be apparent that the construction is fool proof inindicating the required minimum of engagement of the screw threadedconnecting parts.

Having thus fully described the invention, what is claimed as new anddesired tobe secured by Letters Patent of the United States is:

l. A tie rod construction for aircraft use comprising, in combination, arod of uniform cross section having a rounded head, a clevis having athreaded bore to receive the rod, an exteriorly threaded sleeve disposedaround the rod to engage in the bore of the clevis, said sleeve having abore of one diameter for a portion of its length and of a differentdiameter for another portion of its length, the walls of thediiferentportions of the bore being parallel and a curved seat toreceive the rounded head, and a locking means carried by the sleeve toengage the clevis to lock the clevis and sleeve together. Y

2. A tie rod construction for aircraft use comprising, in combination, arod of uniform cross section having a head, a clevis having a threadedbore to receive the rod, an exteriorly threaded sleeve disposed aroundthe rod to engage in the bore of the clevis, said sleeve having a boreof one diameter for a portion of its length and of a different diameterfor another portion of its length, the walls of the different portionsof the bore being parallel and said'sleeve having fiat portions on theoutside to indicate a required v engagement between the sleeve and theclevis and a lock nut on the sleeve to bear against the clevis to lockthe parts together.

3. A tie rod construction for aircraft use comprising, in combination, arod of uniform cross section having a head, a clevis having a threadedbore to receive the rod, an exteriorly threaded sleeve disposed aroundthe rod to engage in the bore of the clevis, said sleeve having flatportions on the outside to indicate a required engagement with theclevis and a locking means to lock the sleeve and clevis togethercomprising a tubular member to surround the sleeve and-engage theclevis, said tubular member having angular faces to engage the atportions on the sleeve.

4. A tie rod construction for aircraft use icomprising, in combination,a rod of uniform cross section having a head, a clevis having a threadedbore to receive the rod, an exteriorlythreaded sleeve disposed aroundthe rod to engage in the bore of the clevis, said sleeve having atportions on the outside to indicate a required engagement with theclevis and a locking means to lock the sleeve and clevis togethercomprising a tubular member to ,surround the sleeve and engage theclevis, said tubular member having angular faces to engage the flatportions on the sleeve, and having ears adapted to be upset after thestructure is assembled to lock the tubular member to the clevis.

5. A tie rod construction for aircraft use comprising, in combination, arod of uniform cross section having a head, a clevis having a threadedbore to receive the rod, an exteriorly threaded sleeve disposed aroundthe rod to engage in the bore of the clevis, said sleeve having areduced portion to indicate a required engagement with the clevis and alock nut on the reduced portion to lock the parts together.

6. A tie rod construction for aircraft use comprising, in combination, arod of uniform cross JAMES H. STEENSON.

